Apparatus for barking logs



Aug. 2, 1938. J. D. ULLGREN APPARATUS FOR BARKING LOGS Filed Nov. 7; 1935 2 Sheets-Sheet l /v we 1933- J. D. ULLGREN APPARATUS FOR BARKING LOGS Filed Nov. 7, 1955 2 Sheets-Sheet 2 Patented Aug. 2, 1938 APPARAT.US FOR BARKING LOGS ":Iohan Daniel Ullgren, Stocksund, Sweden, as-

signor it'o iRuthsacoumlila'tors Nordiska Aktierbola'g, Stockholm, *Sweden, a corporation of Sweden Application November 7, 1935,"SerialNo. 48,781 In Sweden November '7, 1934 4 Claims.

For a considerable time 'past so-called barking drums have been usedfor barking timber. "These consist of very large,rotating-drums, cylindrical or conical in' shape. The object of "the i5 latter form isthat the logs :should automatically "leave the rotating drum at one end. The considerable volume and weight of these drums makes them eXpensive'in-initial cost and inworking, and the journalling of the same presents considerable difliculties. In addition, they "are 'unsatisfactory in worksince, whenworking-continuously, less than half of the drum 'can be =filled withtimber so that the efiectivepart of'the drum is small. Further, the wall of the drum iT5 'only produces an inconsiderable die-barking of the timber since the logs which are adjacent tothe'wall are during the rotation at rest with relation to it.

In order to avoid these disadvantages in the use'of barking drums, it has-been proposedto use stationary barking apparatus, open 'at the top "and in'which the logs are supported'by chain- 'conveyers. When these chains are caused to -move in a given direction, the bundle of wood lying 'on them is caused to rotate in a similar manner to that which'takes placein a barking 'drum.

However, these open barking apparatus suffer from the same drawback 'as the barking drums,

*Viz., that the logs adjacent to the chain-conveyers'acquire very little or no individual rotary motion, wherefore the barking effect of these machines 'is unsatisfactory. 'In addition, the guiding efiect'of the chains is inadequate so that '35 'the logs easily take up other'positionsthan the parallel one which is requisite for eiTectivedebarking.

It has also been proposed to use "open *barking apparatus consisting of a container'filled with 40 water in which the logs fioat and are caused to move by a series of rollers supporting the logs heating .in the water. Inthis 'casethe rollers are *provided with longitudinal grooves LOT ridges, Which when the rollers are rotated, catch the logs and strike them so .as to move forwards. -Due to the form of the rollers the wood of the legs is easily damaged.

The principal object of 'applicants invention is.to construct a-barking apparatus whichmakes it possible to execute the barkingprocess in .an eflicient manner at the sametime so that the Wood of the logs is not damaged.

This is rendered possible according to the present invention 'by using'rollers which are -prismatical in shape with'flat 'or'practicallyfia't surfaces and a suitablenumber of'sides. Thus, their cross-sections may have three or more sides, the number of sides being adapted to the thickness of the logs. For thick logs, it'is suitable to use rollers with three or four sides while, i=5 'forthinner logs, the numberof sides may suitably be six or eight. It is, however, generally -more suitable for-manufacturing reasons to have aneven number of sides.

It has been found in practice that the indi- 10 vidualrotationof the logs in the spaces between the rollers ismuch better when the rollers are prismatical in shape thanif they are practically round or provided with grooves or otherwise -roughened, in which caseblows on the wood from 15 these irregularities cannot be avoided. When using rollers with aprismaticalcross-sectionnot only an individual rotation but also a jumping motion is effected which contributes to increase the de-barkingefiect. i213 Some forms -of construction of the barking machine according to-the present invention are shown in the accompanying-drawings.

Fig.1 shows a machine invertical section. Fig.

2 shows another form of apparatusin vertical :25 section, one portionof'the bottorn being formed by prismatic rollers and the other portion by a chain conveyer. Fig. 3 s'howstheend wall and the prismatic rollers on -a larger scale. Fig. 4 showson a-still larger-scaletwoprismatic rollers (30 withtwo logs in a position which said rollers take during the barking process. Figs. 5 and*6 show 'otherpositions takenby the prismatic rollers'and the logs during the barking process.

According 'to Fig.'1prismatic rollers la and .lb 35 are rotatablymountedbetween two end walls=59, only-one being visible in Fig. -1. The bearings of the axles of the rollers are arranged along straight lines forming an angle with oneanother, the pointer the angle being at .thellower part of the apparatus. :Between the end walls-59 and the rollers there is thus formed a workingchamber 2. In-this working chamber and supported by the :rollers 1 axand I b; are thelogs -3. When the rrollers rotate the :bundle of logs is caused to execute .a ,wandering movement, and each logis given anindividual rotation in .the interstices between the rollers. The rollers are placed soclose to each otherthatthe logs cannot fall between the interstices, but farenough apart for allowingthe'logs 50 to enter partly said interstices, so that therollers when rotated may be able by pairsto cause "the logs between them'to rotateindividually. The peripheral speed ofthe rollers may be uniform for all-the rollers or, alternatively, the speed may'in- 55 gons are parallel.

short rollers H) with circular section and located at right angles to the rollers la and lb. For this purpose the lowermost rollers Ia and lb are arranged at a greater distance from each other than the other rollers, and the rollers i ll enter into the space between said rollers. By these cross rollers l 0 the bark is effectively removed and enabled to escape downwards between these cross rollers.

Fig. 2 shows another form of embodiment in 1 which between the end walls 59 there are rotatably located prismatic rollers I8, the shafts of which are arranged along a straight line sloping towards the bottom. These rollers thus form one part of the bottom of the working chamber. The other part of the bottom of said chamber consists of a chain conveyer is of the usual kind, the chain conveyor being inclined at an angle towards the rollers l8. The chain conveyer i9 passes around the chain wheels 20 and 2E and is provided with catches 23, by which the barked logs are fed out of the apparatus.

Fig, 3 shows on a larger scale different positions of the prismatic rollers and of the logs during the debarking operation.

. Figs. 4, 5 and 6 illustrate how the logs are rolling in contact with the flat sides of the rollers. In Fig. 4 the rollers are in such a position that the upper and lower sides of the hexa- When the rollers rotate the logs roll on the flat sides of the rollers. .Fig. 5 shows how the logs in one position of the rollers rest on the flat sides, the upper log according to Fig.4 then pushes the other log forwards so that it finally comes into the position shown in Fig, 6

.when it is carried over into the interstice between the adjacent rollers.

It is obvious that the rollers must be placed at such a distance from each other that the corners .of the prisms do not touch when they rotate but,

at the same time, the spaces between the rollers mustnot be so large that the logs can fall through when the, rollers are in the position in which the interstices arelarger.

In order that the rolling of the logs on the rotating prismatic rollers may be as ideal as possible it is preferable that all rollers should have the same number of sides, that they rotate with the same speed, effected by means of a chain ';drive as shown in Figs. 4 and 5 or a geared drive as shown in Fig. 6, and that they are so arranged that the corresponding sides of two adjacent rollers are parallel to each other during the ro- ,tation. As a result of this a log resting on a pair of adjacent rollers is given the same peripheral speed by each of the rollers, so that the risk of jamming, especially in the case of thin logs, is

reduced; In order further to reduce this risk itis advisable that the corners of the rollers be somewhat rounded.

. Inthe drawings the rollers are shown mounted on axles through their centres. It is, however,

possible" to have all or some of the rollersex- "centrically journaled as a result of which the jumping motion of the logsobtained by using prismatic rollers is still further increasedav This jumping motion effects an efiicient removing of the bark.

In Fig. 3 the bearings of the rollers are on each side arranged along an arc of a circle, but, as results from the other figures they may also be arranged along straight lines forming an angle with one another. The main point is that a working chamber is formed, in which the part, on which the logs lie, consists wholly or partly of rotatable prismatic rollers.

. What I claim is:-

1. Apparatus for barking a bundle of logs comprising in combination a frame, side-walls on said frame, a number of parallel prismatic rollers with at least three plain sides and saidside walls, said rollers being placed at such a distance from one another that the logs placed parallelly with the rollers cannot fall through the interstices between them, but only partially enter into said interstices, means for imparting rotary motion to said rollers during the work of the apparatus, so that the bundle of logs is given a circular rotary motion and the logs in the interstices between the rollers are given an individual rotary motion and a jumping motion, means for feeding logs into the container and means for ejecting barked logs from the same. I

2. Apparatus for barking a bundle of logs, comprising in combination a frame, side-walls on said frame, a number of parallel prismatic rollers with at least three sides and journaled in said frame, so as to form at least one part of the bottom of a container between said side-walls, said rollers being placed at such a distance from one another that the logs cannot fall through the interstices between them, but only partially enter .rollers are given an individual rotary motion and at the same time a jumping motion.

3. Apparatus for barking a bundle of logs, comprising in combination a frame, side-walls on the said frame, a number of parallel prismatic rollers with at least three sides and journaled in said frame so as to form at least one part of the bottom of a container between said side-walls, two adjacent rollers being located at a larger distance from one another, cross-rollers located in the space between said adjacent rollers in such way that their axles form right angles to the axles of the prismatic rollers, said cross-rollers beingadapted to rotate in pairs in opposite directions, and means for imparting rotary motion to said rollers and said cross rollers during the work of the apparatus.

4. Apparatus for barking a bundle of logs, comprising in combination a frame, a number of parallel prismatic rollers with at least three sides and journaled in the said frame, so as to form one part of the bottom of a container between the said side-walls, the other part of said bottom being formed by chain conveyors, the logs being placed parallelly with the rollers and the rollers being placed at such a distance from one another that the logs cannot fall through the 15 interstices between them, but only partially enter into said interstices, means for imparting rotary motion to said prismatic rollers and chain conveyers during the Work of the apparatus, thereby imparting a circular rotary motion to the bundle of logs and an individual rotary and jumping motion to the logs in the interstices between the rollers, means for supplying logs to the working chamber of the apparatus and means for rejecting barked logs from the same.

J OHAN DANIEL ULLGREN. 

